Fluorite with Quartz coating

Physical Properties

Hardness: Fluorite is 4, Quartz is 7. Color: Purple/Honey Fluorite with white druzy quartz. Luster: Vitreous to sugary. Crystal structure: Cubic (Fluorite) and Hexagonal (Quartz).

Formation & Geological History

Formed in hydrothermal veins where hot mineral-rich fluids circulate through host rock. Often occurs in association with lead and zinc ores in sedimentary or igneous environments.

Uses & Applications

Used as a flux in steel making, in the production of hydrofluoric acid, as a source of fluorine for water fluoridation, and as popular cabinet specimens for collectors.

Geological Facts

Fluorite is known as the most colorful mineral in the world. It often exhibits fluorescence under ultraviolet light and was the mineral used to define the term 'fluorescence' itself.

Field Identification & Locations

Identify by its cubic cleavage under the coating and the fact that it can be scratched by a steel pocketknife (unlike the quartz coating). Commonly found in Illinois (USA), Mexico, and China.

Identified on: 4/19/2026

Mode: Standard